Building an Earthbag Home
Building an earth bag home is a key way to stay green and help benefit the earth by using natural materials. Environmentally friendly homes are becoming more popular than ever before and prove to be energy efficient and low cost. There are some limitations to these homes, as they obviously cannot be constructed into mansions, but with some careful planning and close working with individual building codes from your area can result in a wonderful home for you to enjoy with low energy consumption costs. Taking all of this into account, you will also need the materials to build your earthen home.
Materials for the home can be obtained from the actual area in which you build your home. You need to make sure that the area in which you are building has adequate amounts of available earth within the property, or else you might have to actually bring in earth from somewhere else! You have to also make sure that there is no exposed piping or other underground lines in the area where you wish to build so that you do not destroy expensive communications lines or hit a gas vein.
Mainly, the materials needed will be earth from the area, plaster or stucco, earth bags (burlap bags or polypropylene bags are used), minimal wood and metal depending on your stairs, window and door needs. Shorter homes will take much less materials and will be sturdier. Homes that have more than one floor are a little more difficult to create and may also call into use more building materials such as wood and metal. Although it may seem like a lot of materials once sorted out, it does cost much less than a traditional wooden or prefabricated home. The final design for the home may differ slightly from your initial view, but each home is unique and very easy to build.
The only disadvantages to such a home would have to deal with materials used to build the home. You can really use almost any material for earthen bag homes. Anything from dirt, sand and gravel to rocks and even rice hulls can be used for the homes but other have higher moisture content which can be detrimental to the final structure. Water may leak into the home if the outer walls are not completely filled in and are not coated with enough stucco or plaster material. These homes are also not suitable for very moist climates or areas with hurricanes, tornadoes or earthquakes for structural integrity reasons!
June 22nd, 2009 at 3:17 pm
I am pleased to see that you are suggesting that people consider earthbag building as a viable alternative to conventional building techniques. Since I built my own home with earthbags about a decade ago, and now manage a website that is just about this (www.earthbagbuilding.com) , I have a particular interest in promoting the concept.
Polypropylene bags are generally preferred since they will not be affected by moisture and are stronger than burlap, however you do have to be careful to keep them away from exposure to the sunlight, since the UV rays will deteriorate the material. Another prime ingredient of earthbag building is barbed wire, which is strung (usually two lines of it) between each course of bags. This helps hold the walls together and makes the structure much more earthquake resistant.
The ideal type of soil to fill the bags with is a mix of some clay and some sand, because this will pack into a rather solid block when moistened and compacted, similar to adobe blocks. A very fine, loose sand can actually be a problem because it may not pack well and is vulnerable to shifting its shape later. I used a crushed volcanic stone know as scoria to build my house in Colorado, and this worked out well because it is a natural insulating material…as are the rice hulls.
Earthbag building is extremely versatile in the styles that can be made; they are especially well-adapted to circular and domed structures, but more conventional vertical walled buildings are also possible. In all cases it is important to pay attention to engineering requirements to assure stability. For instance vertical walls may require periodic buttressing. Domes have actually been proven to be very resistant to the forces of earthquakes.
Earthbag buildings have been successfully constructed on every continent and in most climates, including fairly humid places. As with most other methods of building it is important to pay attention to drainage and roof design to keep the bulk of the moisture well away from the walls. Earthbags have the advantage of being able to tolerate moist situations, and they are actually being used as foundations (along with rubble trenches) as foundations for other types of building, such as straw bales.
I suggest that you take a look at my website and you will be amazed at all the ways that earthbags have been used around the world!